1. Field of the Invention
The present invention relates to a miniature display device appropriate for use in a small-sized electronic apparatus such as a hand-held mini-computer. More particularly it relates to a display device used in a hand-held mini-computer, such as a paging system and a data collecting device, acting as a selected calling receiver. This device may be carried in a local station by each of workers, for example, in a building or factory or by each of a plurality of salesmen in a business office. Any receiver can be specified as a local station by a calling signal sent from a central station provided in a control room in a factory in an office. The central station sends a message signal to a receiver in a local station so that the received message signal is displayed on the display device provided on the receiver.
2. Description of the Prior Art
In a paging system, for example, different from a transceiver for vocal communication, a message signal is mainly sent from a central station to each of selected calling receivers in local stations via one-way transmission. The receiver can be made so small-sized as to be carried by a worker in his pocket. Moreover, different from a pocket bell utilized only for calling out, there is an advantage in a paging system in that a message signal is received by a receiver to be stored in a memory unit. Therefore, the contents of the message received by the receiver can be displayed on a display unit so as to be visualized.
Also, in a mini-computer such as a data collecting device, there has been generally provided a display unit composed of e.g. LCD (Liquid Crystal Display) or EL (Electro Luminescence) display elements.
However, in order to display a large amount of data on the display unit in the selected calling receiver device, it is necessary to provide a display unit with a large display frame of, for example, a CRT (cathode ray tube), LCD and EL display. Thus, in this case, the scale of the receiver becomes so large that it is inconvenient for use as a hand-held type receiver. Therefore, the receiver is provided with a display unit capable of displaying only, at most, several characters or numerals. Accordingly, a large volume of data as displayed on the display unit in the central station can not be displayed on the display unit in the receiver. In other words, the display of the message is limited, so that such a conventional display unit has been inconvenient for practical use.
Also, the display unit of the mini-computer must be provided with line display elements of, for example, LCD or EL, so as to be a large scale display unit with a large frame.